1. Field of the Invention
The field of the invention is data processing, or, more specifically, methods, apparatus, and products for transferring a logical partition (‘LPAR’) between two server computing devices based on LPAR customer requirements.
2. Description of Related Art
The development of the EDVAC computer system of 1948 is often cited as the beginning of the computer era. Since that time, computer systems have evolved into extremely complicated devices. Today's computers are much more sophisticated than early systems such as the EDVAC. Computer systems typically include a combination of hardware and software components, application programs, operating systems, processors, buses, memory, input/output devices, and so on. As advances in semiconductor processing and computer architecture push the performance of the computer higher and higher, more sophisticated computer software has evolved to take advantage of the higher performance of the hardware, resulting in computer systems today that are much more powerful than just a few years ago.
One area in which computer software has evolved to take advantage of high performance hardware is a software tool referred to as a ‘hypervisor.’ A hypervisor is a layer of system software that runs on the computer hardware beneath the operating system layer to allow multiple operating systems to run on a host computer at the same time. Hypervisors were originally developed in the early 1970's, when company cost reductions were forcing multiple scattered departmental computers to be consolidated into a single, larger computer—the mainframe—that would serve multiple departments. By running multiple operating systems simultaneously, the hypervisor brought a measure of robustness and stability to the system. Even if one operating system crashed, the others would continue working without interruption. Indeed, this even allowed beta or experimental versions of the operating system to be deployed and debugged without jeopardizing the stable main production system and without requiring costly second and third systems for developers to work on.
A hypervisor allows multiple operating systems to run on a host computer at the same time by providing each operating system with its own set of computer resources. These computer resources are typically virtualized counterparts to the physical resources of a computing system. A hypervisor allocates these resources to each operating system using logical partitions. A logical partition, also referred to as a ‘virtual machine,’ is a set of data structures and services that enable distribution of computer resources within a single computer to make the computer function as if it were two or more independent computers. Using a logical partition, therefore, a hypervisor provides a layer of abstraction between a computer hardware layer of a computing system and an operating system layer.